Both, I suppose. But depends on what you're after:
- Hotline: Miami is fast paced and brutal - you go in, murderize people and get points - the more violent the better. The story (if you're into that) is...will make your head spin a bit as it's...well, schizophrenic seems a really good descriptor there. Also, the soundtrack is nice. And I'll leave it at that.
- Bastion is more of an ARPG with less the complexity, really, but a lot of polish. Or perhaps it's an action game with RPG elements - who can tell the difference, I say. At any rate - you play and you have stats and stuff. It's good, the soundtrack is awesome, the story is all right. It is more about the story than Hotline is. And, I must say, the difficulty in Bastion is probably one of the best ways to tackle it from games I've played - you can "pray" to different gods - they will give you a penalty (say, enemies do more damage or die harder) but also a boon (XP and resource bonus), so you can make it as hard as you wish.
If you have to choose only one, then ask yourself this - would you want a game where you can go in guns blazing, swinging bats, knives and whatever else comes at hand to spill a lot of blood and cause lots of pains or would you rather swing a single weapon most of the time and upgrade it and stuff. If the former, then it's Hotline, if the latter - Bastion.